1. Field of the Invention
The present invention relates to a method for punching bodywork components for motor vehicles, in particular bodywork skins in order to install parking-assistance sensors or headlight washers therein, the invention also relates to a punching machine, and to the bodywork components obtained thereby.
2. Description of the Related Art
In the present description, the term bodywork component “skin” is used to designate the wall of the component that presents a face that is visible from the outside of the vehicle once mounted on the vehicle. It is common practice to refer to bumper skins, however the invention also relates to skins for fenders or to skirts, where a skirt is a wall extending a bumper downwards, at the front or the rear of a vehicle.
It is common to use ultrasound sensors in order to provide parking-assistance systems, often referred to by the acronym PDC (for Park Distance Control). In the description below, the term “PDC sensor” is used to designate such ultrasound sensors.
As a general rule, PDC sensors are mounted in groups of three, four, or six on a bumper skin or a skirt, being held on the inside of the bumper by a support, referred to as a PDC support, that is secured to the inside face of the bumper skin. The support holds the PDC sensor in register with an orifice made through the bumper skin.
In prior art, mounting a PDC sensor on a bumper skin requires two distinct operations: initially punching the skin in order to form an orifice; and then fastening the support on the skin in register with the orifice. Those two operations are performed at two distinct workstations, and usually after paint has been applied, such that the bumper skin that is handled in order to be subjected to these two successive processes is at risk of being scratched on being transferred to or put into place in each of those workstations.
It should be specified that orifices are not generally formed in a bumper skin during fabrication of the skin itself, since the presence of PDC sensors is an option that is not to be found on all of the commercial versions of the vehicle. The bumper skins are thus all manufactured in a single basic version having no orifices, and PDC sensors are added subsequently, usually after painting.
The same principles apply to headlight washers incorporated in bumper skins.
What is needed, therefore, is a method and machine that improves forming orifices in bumper skins.